"The best defense against any heat-related illness is prevention. Be extra careful when the heat index is 90 degrees or above. (The heat index tells you how hot it feels in the shade when relative humidity combines with the air temperature.) Always, always drink plenty of water when the heat index is high and avoid caffeine and alcohol. If you must be outdoors, take frequent breaks inside or in the shade,” says Marilyn J. Heine, M.D., a Bucks County emergency physician and member of the Pennsylvania Medical Society.

Recognize these warning signs:

* Pale skin
* Fatigue, weakness
* Dizzy or nauseous
* Sweating profusely
* Rapid pulse
* Fast, shallow breathing
* Muscle weakness or cramps

Dr. Heine explains, “If you experience any of these symptoms, get out of the heat quickly and rest in a cool, shady place. Drink plenty of water or other fluids containing sugar and salt. Do NOT drink alcohol; that can make it worse. If you don’t feel better within 30 minutes, contact your doctor. If heat exhaustion isn’t treated, it can progress to heat stroke.”

If you have elderly family members, make sure that they have air conditioning and that they are using it. Many times they will cut it off to save energy. Drop in on them in the warmest part of the day and see how the house feels. Stress to them that they must run the air conditioning. Then remind them to drink water as well as tea. Tea can dehydrate water will hydrate. The best way is to stay hands on with them through the hot summer months and check in often.

I agree with the other suggestions and advice that's already been given here including to always stay hydrated and to take cover in the shade whenever possible. Taking a sunbrella along isn't a bad idea either, and is actually kind of classy to boot. :-) However, on particularly hot days with high humidity, it may also be best for her to change her plans. There's nothing wrong with driving occasionally with the air conditioning blasting. Why not save the walking for when it's cooler? During the hottest days of the summer, pollution can also play a role. Heat stroke is obviously very serious, but a lot of seniors have respiratory issues as well.

If she really feels that she needs more exercise, why not have her use a treadmill indoors where the temperature and humidity are controlled? I'm young and in great health, and I still feel the effects of being outside on very hot days. There's absolutely nothing wrong with staying inside.

The best ways to avoid heat stroke for the elderly is to ensure they stay hydrated while spending time outdoors, use umbrellas, sunglasses and hats to keep cool. Wear loose fitting clothing to allow ventilation and to keep cool. Try to avoid being in the direct sun, and attend outdoor activities during cooler times of the day, morning and evening.